Information processing apparatus, information processing method, and storage medium

ABSTRACT

One aspect of the present invention provides an information processing apparatus comprising: an acquisition unit configured to acquire the print request from the client; a selection unit configured to select the first printing apparatus when the accumulated power consumption is not more than a first threshold, and selects the second printing apparatus when the accumulated power consumption is higher than the first threshold; and an accumulation unit configured to add a power to be consumed by the printing apparatus selected by the selection unit to process the print request to the accumulated power consumption stored in the storage unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a power control apparatus forcontrolling power for a system including a plurality of printingapparatuses and a method of controlling the same.

2. Description of the Related Art

Many recent printing apparatuses are provided with a reducing powerconsumption function, which is called an energy saving mode or a sleepmode. For example, a printing apparatus incorporates a timer. When theuser access interval to the printing apparatus exceeds a predeterminedtime, power to the printing apparatus is partially or wholly shut downusing the internal timer. Power consumption reduction is thusimplemented. Several power saving levels are configured for the energysaving mode. As the power saving level becomes higher, the printingapparatus shifts to an energy saving mode for larger power consumptionreduction.

According to the related art, the higher the power saving level is, thelonger the time to return to a printable state is. Hence, a generaltrend indicates that as the energy saving level rises, the convenience(servability) for the user becomes poorer. In a printing system formedby connecting a plurality of printing apparatuses to a network, theprinting apparatuses independently receive access generated by the hostat random. For this reason, the control mechanism of the energy savingmode cannot effectively function in such a system.

To cope with this problem, Japanese Patent Laid-Open No. 2000-322161proposes a power control method that defines the relationship betweenthe power load of an entire network and a service capabilityrepresenting servability as a numerical value. These values are comparedto set such a power consumption that implements servability close to theservice capability and more than the capability. This power controlmethod makes it possible to reduce power consumption to provide aservice more than the currently necessary service capability. At thesame time, the necessary servability can be ensured without causingdeterioration of the servability.

The power control method of Japanese Patent Laid-Open No. 2000-322161can control to make power consumption approach the minimum valuenecessary for implementing the service. However, it is difficult tocontrol the power consumption to a given target power consumption orless. Additionally, control is cumbersome because the load of the entirenetwork needs to be measured periodically.

SUMMARY OF THE INVENTION

In order to solve the above-described problems, the present inventionprovides a power control apparatus capable of efficiently suppressingpower consumption to a target power consumption or less by power controlbased on the target power consumption in consideration of a changinguser service, and a method of controlling the same.

According to one aspect of the invention, an information processingapparatus that includes a storage unit configured to store anaccumulated power consumption, within a predetermined period, of aprinting apparatus group including a first printing apparatus and asecond printing apparatus whose performance and power consumption uponprinting are lower than those of the first printing apparatus, and uponreceiving a print request from a client, selects a printing apparatus toexecute the requested printing from the printing apparatus group basedon the accumulated power consumption, comprises: an acquisition unitconfigured to acquire the print request from the client; a selectionunit configured to select the first printing apparatus when theaccumulated power consumption is not more than a first threshold, andselects the second printing apparatus when the accumulated powerconsumption is higher than the first threshold; and an accumulation unitconfigured to add a power to be consumed by the printing apparatusselected by the selection unit to process the print request to theaccumulated power consumption stored in the storage unit.

According to another aspect of the invention, an information processingmethod to be performed by an information processing apparatus thatincludes a storage unit configured to store an accumulated powerconsumption, within a predetermined period, of a printing apparatusgroup including a first printing apparatus and a second printingapparatus whose performance and power consumption upon printing arelower than those of the first printing apparatus, and upon receiving aprint request from a client, selects a printing apparatus to execute therequested printing from the printing apparatus group based on theaccumulated power consumption, comprises the steps of: acquiring theprint request from the client; selecting the first printing apparatuswhen the accumulated power consumption is not more than a firstthreshold, and selecting the second printing apparatus when theaccumulated power consumption is higher than the first threshold; andadding a power to be consumed by the printing apparatus selected in theselecting step to the accumulated power consumption stored in thestorage unit.

According to the present invention, power consumption is efficientlysuppressed to a target power consumption or less by power control basedon the target power consumption in consideration of a changing userservice.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing printing apparatus categories based onpower thresholds;

FIG. 2 is a figure illustrating a sequence in performing network printprocessing;

FIG. 3 is a view showing an example of the user window screen of aclient of a print manager;

FIG. 4 is a view showing an example of the layout of printingapparatuses and PCs;

FIG. 5 is a figure illustrating an operation sequence in copying via aclient PC;

FIG. 6 is a figure illustrating an operation sequence in copying withoutintervention of a client PC;

FIG. 7 is a block diagram showing power control in a printing apparatus;

FIG. 8 is a view showing the relationship between the power savinglevels and the power shutdown regions;

FIG. 9 is a view showing the process of calculating power consumptionfrom power tables;

FIGS. 10A to 10C are views showing examples of power tables in therespective processes;

FIGS. 11A to 11C are views showing power consumption calculation in therespective power table dispositions;

FIG. 12 is a graph showing an example of monthly power consumptions ofthe printing system on a full-year basis;

FIG. 13 is a table showing monthly target power consumptions consideringmonthly weights;

FIG. 14 is a view showing examples of power thresholds for variouspatterns;

FIG. 15 is a view showing an example of a power control determinationtable;

FIG. 16 is a view showing an example of a power control condition table;

FIG. 17 is a view showing the shift time of an energy saving modecorresponding to a power threshold;

FIG. 18 is a view showing the power control state of the printing systembased on the power control condition table;

FIG. 19 is a view showing an example of use of a temporary printingapparatus;

FIG. 20 is a view showing an example in which grouping control breaksdown;

FIG. 21 is a view showing alternative processing in case of a failure ina selected printing apparatus;

FIG. 22 is a view showing alternative processing in case of a failure ina designated printing apparatus;

FIG. 23 is a flowchart illustrating a sequence of PC-side processing innetwork printing;

FIG. 24 is a flowchart illustrating a sequence of PM-side processing innetwork printing; and

FIG. 25 is a flowchart illustrating an example of periodical powerthreshold recalculation.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a block diagram showing the summary of power control of aprinting system according to the embodiment. In this embodiment, powercontrol of a printing system including a plurality of printingapparatuses connected via a network is executed to achieve a target inaccordance with a given target power consumption 101.

More specifically, an arbitrary number of power thresholds 102 areprovided in correspondence with the target power consumption 101. Threecategories of printing apparatuses in the printing system, that is, aprinting apparatus 103 designated to be used mainly, a printingapparatus 104 designated to be used temporarily, and a printingapparatus 105 selectable by the user are decided based on the powerthresholds. At the same time as the calculation of the power thresholds102, a device selection pattern 106, a power control pattern 107, and aservice condition pattern 108 are created. The printing apparatuses 103to 105 corresponding to the three categories are decided based on thedevice selection pattern 106. The power levels of each printingapparatus after initial activation and after completion of printprocessing are decided based on the power control pattern 107. Servicedetails such as the location of the output destination printingapparatus, the time until completion of print processing, and usablefunctions are decided based on the service condition pattern 108 incorrespondence with each power threshold. Creation of the three patterns106 to 108 can be done based on calculation of the power thresholds 102,and vice versa.

As described above, the power control of this embodiment ischaracterized by uniquely deciding one of the three printing apparatuscategories 103 to 105 based on the power thresholds 102 and the threepatterns 106 to 108 to achieve the target power consumption 101.Although it is generally difficult to make power saving control and userconvenience compatible with each other, the power control method isimplemented while minimizing deterioration of the user convenience. Eachembodiment will be described below in more detail with reference to theaccompanying drawings.

In the following explanation, a “power threshold” indicates both athreshold value and a print control state when a certain power thresholdis selected. As shown in FIG. 14, a plurality of power thresholds (1 to10) are set in advance. The total power consumption (accumulated powerconsumption) increases as printing is performed, as will be describedlater. One of the plurality of power thresholds is selected such thatthe total power consumption becomes lower than the selected powerthreshold. That is, when the total power consumption increases, a higherpower threshold is sequentially selected. For example, as shown in FIG.16, print control information is associated with each power threshold.That is, a server PM performs print control in accordance with theselected power threshold. However, the present invention is not limitedto use of the table shown in, for example, FIG. 16. For example, in FIG.16, a printing apparatus is selected from three printing apparatusesPRN1 to PRN3. Instead, a printing apparatus may be selected from a firstprinting apparatus and a second printing apparatus.

First Embodiment

FIG. 2 is a view showing a basic procedure for network-printing in aprinting system according to this embodiment. A plurality of printingapparatuses PRN1 to PRN6, a print manager PM 204, and a plurality ofpersonal computers PC1, PC2, . . . serving as terminals on a network 201are connected to the network 201. Numbers S1 to S5 attached to arrows214 to 216 among the PC1, the PM 204, and the PRN1 represent the orderof print processing procedure. The details of processing will bedescribed below in the order of numbers. When printing is to beperformed from the PC1, the following processing procedure is executed.

In S1 (arrow 214), the printing conditions (contents) are transmitted tothe PM 204. The PM 204 analyzes the received printing conditions andselects the optimum printing apparatus PRN1. In S2 (arrow 214), the PM204 notifies the PC1 of the selected printing apparatus.

In S3 (arrow 215), the PC1 transmits print information including theprinting conditions and print data to the designated printing apparatusPRN1. In S4 (arrow 216), the printing apparatus PRN1 transmits the printresult to the PM 204 after completion of the print processing. In S5(arrow 214), the PM 204 transmits the received print result to the PC1.After that, the PC1 notifies the user of the print result, and the usergoes to the PRN1 to pick up the printed product. The series ofprocedures represents the basic processing procedure.

The PM 204 is a print manager that has a server/client relationship witheach host PC. Hence, the server software of the print manager isinstalled in the PM 204, and the client software of the print manager isinstalled in the host PCs such as the PC1 and the PC2. When installingthe client software, the driver software of all printing apparatusescontrolled by the server software is assumed to be installed.

The PM 204 with the server software installed in it executes powercontrol of a target printing apparatus in accordance with the powerthreshold 102 as described with reference to FIG. 1. Note that in theexample of the processing procedure shown in FIG. 2, the PC1 transmitsprint information to the designated printing apparatus PRN1 in S3 (arrow215). However, the PM 204 may also have a print server function. Thatis, the PM 204 may transmit the print information.

FIG. 3 shows an example of a user window screen that is displayed whenthe client software of the print manager installed in each host PC suchas the PC1 or the PC2 is activated. A user window screen 301 includesitems of a print mode 302, a page range 303, a number 304 of printcopies, and an urgency 305. A property screen 307 opens upon clicking ona property button 314 included in the print mode 302. The user can setprint quality 308, paper size 309, print orientation 310, and layout 311on the property screen 307.

As described above, the printing apparatus is basically designated onthe server side of the print manager. That is, the urgency 305 on theuser window screen has a check mark on “auto” by default. However, theuser can designate the degree of his/her urgency (urgent/normal) andselect a printer as settings other than the default in the item of theurgency 305.

When the user clicks on a printer select button 306 in the urgency 305,a printer select screen 312 opens. On the printer select screen 312, theuser can select a printing apparatus with corresponding driver softwareinstalled in it. The printing conditions set in the user window screen301 are transferred to the server of the print manager in S1 (arrow 214)described with reference to FIG. 2, thereby designating the printingapparatus. When the client of the print manager transfers the parametersto the driver software of the designated printing apparatus in S3 (arrow215) of FIG. 2, actual print processing starts.

A group A and a group B shown in FIG. 2 will be described with referenceto FIG. 4. FIG. 4 illustrates a layout 401 of the personal computers PC,the print manager PM 204 serving as the server, and the printingapparatuses PRN1 to PRN8 on a certain floor. The group A is the group ofPCs (55 PCs) close to the printing apparatuses PRN1 to PRN3 in terms ofdistance. Similarly, the group B is the group of PCs (40 PCs) close tothe printing apparatuses PRN4 to PRN6, and a group C is the group of PCs(30 PCs) close to the printing apparatuses PRN7 and PRN8. That is, thegrouping is done in consideration of the distance convenience for theusers who use the printing apparatuses.

As shown in FIG. 2, in response to a print request from the PC1belonging to the group A, the print manager PM 204 selects the printingapparatus PRN1 of the same group. Note that a printing apparatusindicated by “” in each group such as the printing apparatus PRN1 orPRN4 in FIG. 2 is the printing apparatus 103 currently designated to beused mainly in that group.

A printer designated to be used mainly will be referred to as a“designated printing apparatus” hereinafter. A code such as PL0 added toeach printing apparatus indicates a power level designated by the powercontrol pattern 107 corresponding to the level of the power threshold102. Power control will be described later.

Several examples will be explained concerning print procedures otherthan network-printing. FIG. 5 is a figure illustrating the basic printprocedure in copying. A case is assumed in which the user of the PC1 ofthe group A wants to do copy print from his/her desk. Numbers S51 to S54attached to arrows 501 to 503 in FIG. 5 represent the print procedure.

The user of the PC1 checks “copy” in the print mode 302 on the userwindow screen 301 and sets other necessary printing conditions. Whenusing default values, the user need only check “copy”. In S51 (arrow501), the PC1 transmits print information including the printingconditions and print data to the PM 204 to send a print instruction. ThePM 204 analyzes the printing conditions and selects an optimum printingapparatus based on the current power threshold 102. The PM 204 normallyselects the designated printing apparatus in the same group as that ofthe user. In S52 (arrow 501), the PM 204 notifies the PC1 of theselected designated printing apparatus.

In S53 (arrow 502), the PC1 notifies the user of the selected designatedprinting apparatus. The user goes to the PRN1 that is the notifieddesignated printing apparatus to execute a copy operation 504. In S54(arrow 503), the PRN1 transmits the copy print result to the PM 204after completion of copy print.

An example will be described in which the user goes from a place otherthan his/her PC to a printing apparatus to execute printing. FIG. 6illustrates an example in which the user suddenly executes copy print onthe printing apparatus PRN2. Even during power control by the PM 204, itis possible to execute an authentication operation so as to permit aprint action such as copy print in consideration of user convenience.Numbers S61 to S63 attached to a solid line arrow 601 and a broken linearrow 602 in FIG. 6 represent the print procedure.

In S61 (arrow 601), the printing apparatus PRN2 notifies the PM 204 thatthe user authentication operation has ended, and the printing apparatusis set in the standby state ready to print. In S62 (arrow 602), if theprinting apparatus is different from the current designated printingapparatus, the PM 204 performs power control so that the printingapparatus shifts to the power saving mode as needed. If the printingapparatus is operating for, for example, printing, the PM 204 may beprohibited from performing the control. In this case, since the PRN2 isthe designated printing apparatus, the PM 204 sends the copy printpermission to the PRN2.

The PRN2 executes the copy print processing. After completion ofprocessing, in S63 (arrow 601), the printing apparatus transmits theprint result to the PM 204. An example in which sudden copy print by theuser occurs has been described. However, the processing proceduredescribed with reference to FIG. 6 is applicable to direct printing thatexecutes printing by directly connecting a memory device to a printingapparatus or printing a FAX received by FAX reception.

The basic print processing sequence according to the first embodimenthas been described above. Details of the power control method will bedescribed next. Note that the following explanation assumes the layoutof the PM 204, the PRN1 to PRN8, and the like on a certain floor asshown in FIG. 4.

FIG. 7 is a block diagram showing an example of power supply control ina printing apparatus. When an AC line 712 is connected to a wall socket,and an SW unit 71 of the main power supply is turned on, AC power issupplied to an AC-DRIVER unit 701. Various kinds of internal powersources are thus generated. In this embodiment, an all-night powersource, 12V power source, 24V power source 1, 24V power source 2, andheater power source are generated at predetermined timings in theAC-DRIVER unit 701. The generated power sources are basicallytemporarily distributed to the respective blocks via a RELAY unit 702.

Examples of blocks to which power is supplied are a Main controller 703,a user interface UI 704, a Reader 705, a D (device) controller 706, afixing/conveyance system 707, a drum system 708, a feed system 709, adischarge system 710, and a heater system 711. A description of eachblock will be omitted here. Power supply to the blocks 703 to 711 can beon/off-controlled by the RELAY unit 702.

The Main controller 703 performs processing of acquiring input data fromvarious kinds of interfaces (for example, the UI 704, the Reader 705, ora network (not shown)) and generating print data. The D controller 706of the next stage executes processing of printing the print datagenerated by the Main controller 703 on a paper sheet by controlling thefunctions of the blocks 707 to 710 of the printing apparatus main body.The Main controller 703 also executes power supply control of the entireprinting apparatus, as shown in FIG. 7.

The solid line arrows in FIG. 7 indicate power supply lines, and thebroken line arrows indicate control signals. The all-night system of theMain controller 703 indicates the power supply that always continuouslysupplies power even in the power saving mode. A non-all-night systemindicates the power supply that is shut down in the power saving mode.In this embodiment, the Main controller 703 includes one all-nightsystem and two non-all-night systems.

The power supply control procedure will be described. First, the SW unit71 of the AC-DRIVER unit 701 is turned on to supply power to each block.When the Main controller 703 itself is activated by this power supply,the blocks 704 to 710 and the power sources of the AC-DRIVER unit 701are on/off-controlled using a power supply control signal 714 to theRELAY unit 702 in accordance with a predetermined power supply controlsequence. Power saving groups (A) to (E) of the blocks in FIG. 7represent grouping associated with the power saving level. For example,turning off the power supply to the non-all-night system 1 of the Maincontroller 703 means shutting down the power supply to the power savinggroups (A) and (B), that is, the blocks 704 and 705. Turning off thepower supply to the non-all-night system 2 means shutting down the powersupply to the power saving groups (A) to (C), that is, the blocks 704 to710.

The relationship between the power saving levels and the power savinggroups (A) to (E) of the blocks shown in FIG. 7 will be described withreference to FIG. 8. Power shutdown regions 801 of the table shown inFIG. 8 correspond to the power shutdown regions (A) to (E) in FIG. 7.Power saving levels 802 of the table represent power saving levelscorresponding to the power shutdown ranges of the power saving groups(A) to (E). In the table, “∘” indicates a power ON region, and “x”indicates a power shutdown region.

PL0 (Power Level 0) indicates a full power ON state that is the Standbystate in which print processing is immediately possible. At PL1, thepower is shut down in the region (A). At PL2, the power is shut down inthe regions (A)+(B). As the numerical value annexed to PL increases, thepower saving level rises, and the shutdown region becomes large.

PL5 that is the highest level indicates that the power is shut down inall regions, that is, the AC power supply to the printing apparatus mainbody is stopped. This is expressed in FIG. 7 as a configuration in whichan external power supply control unit 713 is arranged outside the ACpower supply line 712 to on/off-control the power based on an externalcontrol signal. As another method, a timer circuit and a backup batterymay be provided in the SW unit 71 of the AC-DRIVER unit 701 toon/off-control the power based on the time set in the timer circuit.Hence, control of the power shutdown region (E) can be done eitheroutside or inside the AC power supply line 712.

A WakeUpTime 803 that is an item of the table of FIG. 8 represents thereturn time from each of the states of power saving levels PL0 to PL5 tothe Standby state. As can be seen, the higher the required power savinglevel is, the longer the return time to the Standby state is. That is,this means that the higher the power saving level is, the poorer theuser convenience is.

The contents described with reference to FIGS. 7 and 8 indicate analready standard technique. As the shift time designations to the powersaving levels, default values set at the time of shipment or values setby the user at the time of operation have been used. In this embodiment,the print manager serving as the server gives the initial value of eachpower saving level of each printing apparatus.

An example of power consumption calculation will be described next. FIG.9 is a view showing the procedure of calculating power consumption usingvarious tables. A full performance table 901 of a target printingapparatus, a power table 902 of the basic configuration, and a powercorrection table 903 are set in advance. The full performance table 901is a list of all functions the printing apparatus can ensure. This listincludes the printing performance, the resolution, the extensionaccessories of the feed system and the discharge system to be added tothe basic configuration, and optional kits such as an IC card and anencryption board. The power table 902 of the basic configurationindicates a reference power consumption in reference processing in theminimum basic configuration of the target printing apparatus. Forexample, when reference processing sets {paper size: A4, layout:single-sided, resolution: 600 dpi, print mode: color, and print quality:standard}, power consumption measured for the reference processing inadvance is the reference power consumption. The power correction table903 is a table to be used to obtain the correction amount from thereference power consumption. This table is used to obtain the expandedconsumption due to the extension accessories and optical kits from thebasic configuration or the correction amount from the referenceprocessing based on actual printing conditions (the number of printingpages, paper size, print mode, print quality, special image processing,and the like).

From the above-described three basic tables 901 to 903, tables for thecurrent configuration corresponding to the three tables are createdbased on the current configuration of the target printing apparatus. Thetables are a performance table 904 of the current configuration, a basicpower table 905 of the current configuration, and a power correctiontable 906 of the current configuration. Power consumption calculation907 for the current configuration is finally executed using the basicpower table 905 of the current configuration and the power correctiontable 906 of the current configuration. The power correction table 906of the current configuration can be regarded as a table obtained byremoving unnecessary functions from the power correction table 903 offull performance to modify it for the current configuration. Theperformance table 904 of the current configuration is used as basic datato create the power control determination table of each printingapparatus to be described later.

A detailed example of the basic power consumption table 905 of thecurrent configuration will be described with reference to FIGS. 10A to10C. FIG. 10A shows an example of a table that creates powerconsumptions in the respective power states and power consumptions uponpower state transition in the current configuration. In this embodiment,the printing apparatus is assumed to have the power saving levelsdescribed with reference to FIG. 8.

This table includes a power state 1001 and a power consumption 1002 inthat state. PL4→PL0 or PL5→PL0 indicates a power consumed at the time oftransition from the power saving level PL4 (or PL5) to PL0 (Standby).According to the table in FIG. 10A, an accumulated value can be obtainedby accumulating power consumptions except that during non-processing,based on the current steady power consumption and the power consumptionat the time of transition. FIG. 10B shows an example of a table thatcreates a reference power consumption corresponding to a resolution 1003and a layout 1004 based on the A4 size and one color-printed page in thecurrent configuration.

The power consumption in actual print processing can be calculated byratio calculation using the power correction table 906 of the currentconfiguration for the printing conditions at that time based on thereference power consumption in the table of FIG. 10B. Note that theconditions that determine the reference power consumption are notlimited to those of the example, and optimum conditions can be selected.

FIG. 10C shows an example of a table that creates a reference powerconsumption in non-print processing. This table includes a processingcontent 1005 and a reference power consumption 1006 necessary for theprocessing. Several representative examples of the non-print processingwill be described. “Scan to Send” is a service that transfers image datascanned by the Reader of a printing apparatus to a designated address onthe network.

“BOX to Send” is a service that transmits data in a Box (hard diskdevice) to a designated address on the network. “Send to BOX” is aservice that stores data transmitted from an external network in the BOXof a designated address.

These processes include no print action but data transmission/reception.Hence, the reference power consumption 1006 in the current configurationis defined for the reference data size of each process. The powerconsumption in non-print processing can also be calculated by ratiocalculation using the power correction table 906 of the currentconfiguration for an actual non-printing condition such as the processdata size based on the reference power consumption 1006, as in printprocessing.

Examples of power consumption calculation will be described next withreference to FIGS. 11A to 11C. FIGS. 11A to 11C show three examples ofcalculation of the power consumption of the target printing apparatus.Referring to FIG. 11A, the power tables 905 and 906 exist on the side ofa print manager PM 1101 serving as a server. The PM 1101 receives aprocessing result report 1103 from a printing apparatus PRN 1102,thereby calculating a power consumption for the processing result report1103 and also calculating the accumulated power consumption of the PRN1102. The processing result report 1103 includes the reports of printprocessing and non-print processing, as described with reference toFIGS. 9 and 10A to 10C. The accumulated power consumption includes thestandby power consumption of each of the levels PL0 to PL5 and thetransition power consumption between the PL levels.

In FIG. 11B, the power tables 905 and 906 are held on the side of thePRN 1102. In this case, the PRN 1102 calculates the accumulated powerconsumption of its own and sends it to the PM 1101 together with aprocessing result report 1104. Based on the received processing resultreport 1104, the PM 1101 updates the accumulated power consumption ofthe PRN 1102 and calculates the total accumulated power consumption ofthe printing system. FIG. 11C shows a form in which the PRN 1102includes a power measuring circuit to actually measure the powerconsumption and sends it to the PM 1101 together with a processingresult report 1105. Based on the received processing result report 1105,the PM 1101 updates the accumulated power consumption of the PRN 1102and calculates the total accumulated power consumption of the printingsystem. This method is accurate because of the minimum error in theaccumulated power consumption. However, the hardware circuit iscomplicated, directly leading to an increase in the cost.

As described above using FIGS. 11A to 11C, power consumption calculationof each printing apparatus according to this embodiment need only beexecuted on the side of either the print manager PM 1101 or the printingapparatus. The power consumption calculation method is not limited tothat using the power table 905 or 906, and any other method is usable ifit can obtain the same result.

A power control method serving as the core of the embodiment will bedescribed below. An example of the method of deciding the powerthresholds 102 for the target power consumption 101 described withreference to FIG. 1 will be explained first.

FIG. 12 is a graph of the power consumption of a printing apparatus onthe certain floor described with reference to FIG. 4 within a monthlyset predetermined period. The power consumption is high in January,June, September, and December, as is apparent. That is, the printingapparatus use frequency is higher in these periods than in the remainingmonths. Assume that a graph 1201 of FIG. 12 represents the result oflast year, and the total power consumption of the printing apparatus isplanned to be lower by 10% this year than that of last year. Let Py bethe annual target power consumption of this year. As described above,the monthly unevenness is large on a full-year basis. For this reason,the annual target power consumption is further decomposed to calculate amonthly target power consumption Pm.

Broken lines 1202 to 1204 on the graph 1201 of FIG. 12 indicateweighting lines to be used to calculate the monthly power consumptionPm. The power consumption corresponding to the weighting line 1203 is1.5 times as high as the power consumption corresponding to theweighting line 1202. The power consumption corresponding to theweighting line 1204 is twice as high as the power consumptioncorresponding to the weighting line 1202. When the monthly minimum powerconsumption unit is defined as P0, P0 is uniformly given as the monthlytarget power consumption to each month where the power consumption doesnot reach the weighting line 1203. A monthly target power consumptioncorresponding to 1.5×P0 is given to each month where the powerconsumption ranges from the weighting line 1203 (inclusive) to theweighting line 1204 (exclusive). A monthly target power consumptioncorresponding to 2.0×P0 is given to each month where the powerconsumption reaches the weighting line 1204.

FIG. 13 is a table that provides a summary of the monthly target powerconsumptions described above. This table includes a monthly power 1301and a power consumption 1302 of each month. The last item indicates themonth sum which equals an annual target power (consumption) Py 1303.Hence, when the annual target power consumption Py 1303 is given, theminimum power consumption unit P0 is obtained, and the monthly targetpower consumption Pm is given.

The power threshold 102 for the given monthly target power consumptionPm will be described next with reference to FIG. 14. A graph 1401 ofFIG. 14 represents an example in which the power threshold 102 isdivided into 10 values in a uniform pattern 1403 with a target powerconsumption Pm 1402 of a certain month defined as the upper limit.Service details to be provided to the user are uniquely determined inaccordance with each of power thresholds 1 to 10.

Two arrows 1404 and 1405 beside the graph 1401 indicate the degrees ofservice priority for the user. In a state with a low power threshold,the service is prioritized due to the higher user convenience priority1404. As the power threshold becomes higher, the pressure on the powerconsumption becomes tighter. Hence, power limitation is prioritized overthe service. That is, as the power threshold comes closer to the monthlytarget power consumption Pm 1402, power control is done to make thepower priority 1405 higher. This means that, for example, the powerconsumption is controlled based on a low power threshold at the start ofa month, but as the month gradually nears the end, based on a high powerthreshold, that is, a threshold closer to the monthly target powerconsumption Pm. That is, at the start of a month, since the allowance tothe target power consumption Pm is large, the use restriction is loose,and the user servability is high. As the time elapses, the userservability lowers, and the use restriction of the printing apparatusbecomes tough.

(B) and (C) of FIG. 14 show other pattern examples different from theuniform power threshold pattern of (A). A service priority pattern 1406in (B) of FIG. 14 is formed by nonuniformly narrowing the interval ofthe uniform pattern 1403 of (A) toward the high power threshold side. Ifthe service details corresponding to the power thresholds of the uniformpattern 1403 are the same, the service priority pattern 1406 indicatesthat, for example, the service priority becomes higher in correspondencewith power thresholds 1 to 5 that are selected for a longer period.

In an energy saving priority pattern 1407 in (C) of FIG. 14, theunevenness of power thresholds is reverse to that of the servicepriority pattern 1406 of (B). In this case, for example, powerthresholds 6 to 10 are selected for a longer period at the time thepressure on the power consumption is tight, and the energy savingpriority is therefore higher. Causing the administrator to set the threepatterns 1403, 1406, and 1407 enables to change the power controlpolicy.

As described above, to decide the power thresholds 102 in FIG. 1, eachthreshold is set in correspondence with the target power consumption tobe set. However, the present invention is not limited to this form. Forexample, the power per hour to be consumed in a day is uneven. In theabove-described example, a relatively small number of power thresholdsare set to eliminate the influence of such unevenness. However, morepower thresholds may be decided to allow the influence of powerconsumption unevenness. In that case, the degree of power consumptionunevenness needs to be taken into consideration to decide the servicedetails corresponding to each power threshold and the power thresholdintervals of the three power threshold patterns 1403, 1406, and 1407 andthe like. When considering the degree of power consumption unevenness,the algorithm of the power threshold deciding method accordingly becomesmore complex.

An example of a power control condition table to be used to designatethe power state of each printing apparatus corresponding to the powerthreshold 102 in FIG. 1 and set the service details will be describednext with reference to FIG. 15. FIG. 15 shows a power controldetermination table 1501 generated in the print manager serving as theserver as a determination material to be used to create a power controlcondition table. This table includes printing apparatuses 1 to 8 plottedvertically and a designated Power level 1502 and a designated Spec level1503 plotted horizontally. Printing apparatuses 1 to 8 correspond to theeight printing apparatuses PRN1 to PRN8 in the example on the certainfloor in FIG. 4.

The Power level 1502 represents the power consumption of each printingapparatus. The Power level 1502 is obtained as, for example, asimulation value for each of models that are predetermined to beactivated from the energy saving mode standby state for a predeterminedperiod to the standby state to perform processing under predeterminedconditions. The power consumption as the simulation value can also beobtained from the basic power table 905 of the current configuration andthe power correction table 906 of the current configuration in FIG. 9.

The power consumption calculated as a simulation value is compared with10 predetermined numerical values, thereby representing the Power level1502 of each of printing apparatuses 1 to 8 as a value. In this case,the larger the numerical value is, the higher the power consumption is,and the lower the capability evaluated by the Power level 1502.Numerical value 5 is the intermediate standard level for printingapparatuses 1 to 8.

The Spec level 1503 represents the functional capability of eachprinting apparatus. Like the Power level 1502, setting, for example, 4as the standard level that can cope with a user's printing condition,six numerical values are predetermined in total around the value 4, andthe evaluation value is obtained from the performance table 904 of thecurrent configuration of each printing apparatus. Regarding the Speclevel 1503 corresponding to each of printing apparatuses 1 to 8, thelarger the numerical value is, the higher the specifications are.

When the Power level 1502 and the Spec level 1503 of the power controldetermination table 1501 are represented by a set (x,y), thedetermination can be done in the following way. For example, printingapparatus 1=(9,6) is determined to “have a high power consumption but bethe best in functional level so as to be able to cope with any user'sprint request”. Printing apparatus 4=(4,4) is determined to, forexample, “be an average printing apparatus in terms of both the powerconsumption and the function”.

An item “Grouping” 1504 of the power control determination table 1501represents grouping of groups A, B, and C in the example on the certainfloor in FIG. 4. In FIG. 15, printing apparatuses 1 to 3 are put intothe group A, printing apparatuses 4 to 6 are put into the group B, andprinting apparatuses 7 and 8 are put into the group C, as indicated bythe broken line rectangles.

A final selection order 1505 represents a printing apparatus be left asthe final candidate when the power threshold has reached several highlevels and its priority order. In the final selection order 1505,printing apparatus 4 is selected as the first candidate, and printingapparatus 8 is selected as the second candidate. The items of theGrouping 1504 and the final selection order 1505 may be set by theadministrator or adjusted by the administrator to optimum conditionscalculated by the print manager PM 204 serving as the server.

FIG. 16 shows an example of a power control condition table 1601 for thegroup A created to control the power consumptions and service details ofprinting apparatuses 1 to 3 in association with the power thresholds102. Power control condition tables for the group B including printingapparatuses 4 to 6 and the group C including printing apparatuses 7 and8 are also created similarly. Service details are plotted horizontallyin correspondence with power thresholds 1 to 11 plotted in the verticaldirection of the table. Note that numerical values 1, 2, and 3 under aPM designation 1602, user selectable 1603, and power saving level 1604represent printing apparatuses 1, 2, and 3 belonging to the group A,respectively.

The PM designation 1602 is an item that indicates a designated printingapparatus designated or selected by the PM 204. In the table, “∘”indicates a designated printing apparatus, “Δ” indicates anon-designated printing apparatus to be used temporarily, and “x”indicates an undesignatable printing apparatus (also the PM does not usethis printing apparatus).

The user selectable 1603 is an item representing whether a desiredprinting apparatus can be selected by the printer select button 306 ofthe user window screen 301 in FIG. 3. “∘” indicates a selectableprinting apparatus, and “x” indicates an unselectable printingapparatus.

The power saving level 1604 is an item representing the power savinglevel of each printing apparatus designated by the PM 204. The powersaving levels (PL1 to PL5) exemplified with reference to FIG. 8 maychange depending on the printing apparatus. The following description ofthe embodiment assumes that printing apparatus 1 has PL1 to PL5,printing apparatus 2 has PL1 to PL4, printing apparatus 3 has PL1 toPL3, printing apparatuses 4 to 7 have PL1 to PL4, and printing apparatus8 has PL1 to PL3 as the power saving levels.

As indicated by the power saving level 1604, the power saving level isset to be lower to prioritize the user convenience when the powerthreshold is low. As the power threshold becomes higher, the powersaving level also gradually rises to prioritize power control.

Print constraints 1 to 3 in an item field 1605 represent thepresence/absence of constraints to be imposed at the time of printprocessing. In the table, “∘” indicates that the constraint is valid,and “-” indicates that the constraint is invalid. As examples of theconstraints, constraint 1 is “double-sided printing”, constraint 2 is“2-in-1 printing”, and constraint 3 is “monochrome printing”.

For example, during the period all constraints 1 to 3 are valid, theconstraints are imposed to forcibly perform 2-in-1 monochrome printingin the double-sided printing mode (that is, 10 pages will be output)even if the user's printing conditions indicate 40-page color printingin the single-sided printing mode. When print constraints 1 to 3 arevalid, the items designatable by the property button 314 of the userwindow screen 301 in FIG. 3 become undesignatable. If the parameters onwhich the constraints are imposed are included in the print requestconditions, the server PM may be prohibited from accepting the printrequest or change the parameters. More specifically, as shown in FIG.16, when power threshold 5 is selected (when the total power consumptionis equal to or lower than power threshold 5), the server PM selects thePRN2 that is the designated printing apparatus even if single-sidedprinting is designated. On the other hand, when power threshold 6 isselected (when the total power consumption is higher than powerthreshold 5), the server PM may be prohibited from selecting the PRN2that is the designated printing apparatus if single-sided printing isdesignated. In this case, printing is not performed. Alternatively, theserver PM may select the PRN2 that is the designated printing apparatusand designate double-printing.

A supplementary explanation will be made concerning control of the powersaving level 1604 with reference to FIG. 17. FIG. 17 shows an example ofan energy saving mode shift time table 1701 to be used to preset theshift time to each power saving level corresponding to a powerthreshold. An expression 1702 “PL1→PL2”, an expression 1703 “PL2→PL3”,an expression 1704 “PL3→PL4”, and an expression 1705 “PL4→PL5” representtimes to shift to an energy saving mode corresponding to a higher powersaving level.

For example, for power threshold 1 of the power control condition table1601, printing apparatus 1 of energy saving level 1 is assigned to thedesignated printing apparatus, and printing apparatuses 2 and 3 areassigned to temporary printing apparatuses. At this stage where thepower threshold is still low, the power saving level of printingapparatuses 2 and 3 is low, too. Hence, the standby power consumption ishigh, resulting in waste of power without access.

In this case, control may be done to make only designated printingapparatus 1 stand by at the power saving level PL1 and shift temporaryprinting apparatuses 2 and 3 to a higher energy saving mode inaccordance with the energy saving mode shift time table 1701. The powersaving level 1604 of the power control condition table 1601 does notalways indicate a fixed power saving level but indicates a designatedpower saving level at the time of initial activation and upon completionof processing. Control may be done to fix the power saving level, as amatter of course.

The above-described power control condition table 1601 is created by thePM 204 based on the performance tables 901 and 904, the basic powertables 902 and 905, and the power control determination table 1501 ofeach printing apparatus. The power and service details of each printingapparatus are controlled in accordance with the power threshold based onthe power control condition table 1601.

At the stage the power threshold is low, the position convenience(grouping), the convenience of print process time (time shortening usinga low energy saving mode or a temporary printing apparatus), and theconvenience of usable functions for the user are prioritized over powersaving control. However, as the power threshold becomes higher, that is,as the power consumption approaches the monthly target power consumptionPm, control shifts to prioritize power saving while sacrificing theservice convenience for the user.

As the control items of the power control condition table 1601, thenumber of power thresholds, the PM designation, the user selectable, thepower saving level, and constraints 1 to 3 have been exemplified.However, the items are not limited to those. The number of powerthresholds or power saving levels can be decided based on the controlconditions corresponding to them, and vice versa. Alternatively, theymay be decided independently. That is, the above-described creationalgorithm of the power control condition table 1601 is merely anexample, and the present invention is not limited to this.

FIG. 18 illustrates a state in which the eight printing apparatuses PRN1to PRN8 controlled based on the power control condition table 1601 arecontrolled in accordance with the levels of power thresholds 1 to 11.Symbols in FIG. 18 will be explained first. Each bold line rectanglerepresents a printing apparatus. A hollow rectangle represents aprinting apparatus selectable by the user, and a hatched rectanglerepresents a printing apparatus unselectable by the user. PL1 to PL5added to the rectangles represent power saving levels. A symbol “”indicates a designated printing apparatus, and a symbol “x” indicatesthat the printing apparatus is unusable as a temporary printingapparatus. Note that the printing apparatuses other than those given “x”always have the possibility of being used as a temporary printingapparatus.

Based on the example of the certain floor described with reference toFIG. 4, a column 1801 indicates the group A (printing apparatuses PRN1to PRN3), a column 1802 indicates the group B (PRN4 to PRN6), and acolumn 1803 indicates the group C (PRN7 and PRN8). Each group isindicated by a broken line rectangle. A column 1804 indicates the levelsof power thresholds 1 to 11.

As is apparent from comparison between the power control determinationtable 1501 and the power control condition table 1601, as the powerthreshold lowers, a more advanced printing apparatus is selected as thedesignated printing apparatus, and the number of types of printingapparatuses freely selectable by the user increases. At the same time,the power saving level is also low so that the printing apparatus is setto be able to immediately react to a user's print request. That is,control is performed to prioritize the convenience for the user at lowpower thresholds 1 to 6.

Reversely, as the power threshold rises, a printing apparatus with lowpower consumption is selected as the designated printing apparatus, andthe number of printing apparatuses selectable by the user graduallydecreases. In addition, the power consumption is controlled to alwaysset a high power saving level. That is, control shifts to prioritize thepower while sacrificing the convenience for the user at the high powerthresholds (power thresholds 7 to 11).

This means that each group includes a designated printing apparatus whenthe grouping effectively functions. As is apparent, the grouping controleffectively functions up to power threshold 9 but breaks down for powerthresholds 10 and 11. For example, only the PRN4 and PRN8 operate forpower threshold 10. For power threshold 11, only the PRN4 operates onthe entire certain floor in FIG. 4.

Note that the printing apparatuses PRN4 and PRN8 selected after thegrouping has broken down are those set by the final selection order 1505in the power control determination table 1501. According to the order ofthe final selection order 1505, the printing apparatus that remains forpower threshold 11 at the final stage is the PRN4. Comparison betweenthe group B and the remaining groups A and C proves that the PRN5 isnever the designated printing apparatus in the group B.

When the Power level 1502 and the Spec level 1503 of the power controldetermination table 1501 in FIG. 15 are represented by a set (x,y),PRN5=(6,3). That is, the functional performance is low relative to thehigh power consumption. Hence, a printing apparatus like the PRN5 isnever selected as the designated printing apparatus, and is usable onlywhen selected by the user or by the PM 204 as the temporary printingapparatus.

An example will be described in which control of the designated printingapparatus and the temporary printing apparatus is performed in two casesof the low power threshold state (power thresholds 1 to 6) and highpower threshold state (power threshold 11) under the power controlsituation in FIG. 18.

FIG. 19 shows an example of use of the temporary printing apparatus.

Here is assumed a scene where heavy print jobs 1901 concentrate to thedesignated printing apparatus PRN1. In this scene, when a low powerthreshold is selected (first power threshold), the PM 204 executescontrol to distribute print jobs 1902 to the temporary printingapparatus PRN2 as well in consideration of the servability of printprocess time shortening for the user.

The sequence in processing between the PCs and the PRN1 and PRN2 of thegroup A is indicated by a solid line 1903 and a broken line 1904. Theprocedure of the sequence is the same as that described with referenceto FIG. 2, and a description thereof will not be repeated. The PRN2serving as the temporary printing apparatus is controlled to shift tothe power saving level corresponding to the current power thresholdagain after completion of processing of the print jobs 1902.

When a high power threshold is selected, the temporary printingapparatus is not used, unlike the above-described case, because powersaving is prioritized over the user convenience, as a matter of course.However, the temporary printing apparatus may temporarily be used whenthe current designated printing apparatus cannot satisfy the printrequest conditions or a trouble such as a failure or paper jam hasoccurred.

FIG. 20 shows a print processing sequence 2001 for power threshold 11 inFIG. 18. The procedure of the print processing sequence 2001 is the sameas that described with reference to FIG. 2, and a description thereofwill not be repeated. For power threshold 11, only the PRN4 operates onthe entire floor, as described above. At this time, all the PRN1 to PRN3of the group A are unusable. Hence, even when a print request is issuedby the PC1 of the group A, the PM 204 selects the printing apparatusPRN4 of the group B. That is, in this case, grouping control isabandoned, and the position convenience for the user is lost.

As described above, a plurality of printing apparatuses on a floor areuniquely categorized using the power thresholds, the device selectionpattern, the power control pattern, and the service condition pattern onthe power control condition table, thereby executing power control forthe target power consumption.

Second Embodiment

In the second embodiment, processing to be performed by the powercontrol system described in the first embodiment when a failure hasoccurred will be described. FIG. 21 is a view showing processing ofdealing with a failure in the selected printing apparatus. Here isassumed a case in which a failure has occurred in a printing apparatusPRN1 designated by a PM 204 for print requests from a PC1 and a PC2.

Examples of the failure are a jam error such as paper jam, an expendableerror such as paper-out or toner exchange, and a fault. Upon detectingthe failure in the PRN1, the PM 204 analyzes the current power controlstate and print job contents 2402 and selects an optimum alternativeprinting apparatus corresponding to the power threshold.

In FIG. 21, an PRN2 that belongs to the same group A and is alreadyprocessing as the alternative printing apparatus and an PRN4 thatbelongs to a group B and serves as the current designated printingapparatus are selected. In this case, the position convenience and theconvenience of print process time for the print requesting user aretaken into consideration, in view of the power threshold.

The PM 204 cancels the print job contents 2402 of the PRN1 and transmitsthe error details and information of selected alternative printingapparatus to the PC1 and the PC2 as the print request sources, therebysending a print job resend instruction 2401. The print manager (client)of each request source that has received the resend instruction resendsthe print jobs to the designated alternative printing apparatus.

The PC1 resends a print job 2404 to the alternative printing apparatusPRN4, whereas the PC2 resends a print job 2403 to the alternativeprinting apparatus PRN2. Print processing and calculation of powerconsumption therefor in each alternative printing apparatus are the sameas the already described contents. Assume that the resend instructioncontents from the PM 204 represent that, for example, the error is a jamerror or an expendable error, and a part of the printing is completed.In this case, continuation page information may be added to theinstruction contents so that the alternative printing apparatus couldstart print processing continued from there. Alternatively, the PM 204may notify the administer level user of the contents of the failure inthe printing apparatus.

The printing apparatus where the failure has occurred is excluded fromthe printing system by the print manager (server) until removal of thefailure. Especially when the printing apparatus with the failure is adesignated printing apparatus, an alternative designated printingapparatus is necessary.

FIG. 22 is a view showing selecting an alternative to the designatedprinting apparatus. The PM 204 excludes the designated printingapparatus PRN1 with the failure, and selects the printing apparatus PRN2planned to be the next designated printing apparatus on a power controlcondition table 1601 described with reference to FIG. 16 as analternative designated printing apparatus 2501.

Although not illustrated here, whether the PRN1 will return to thedesignated printing apparatus again after removal of the failure isdetermined based on the power threshold at that point of time. It ispossible to determine, based on the power threshold at that point oftime and the power control condition table 1601, whether the PRN1 can bethe designated printing apparatus.

As described above, in the second embodiment, even when a failure hasoccurred in the designated printing apparatus of the system under powercontrol, it can be solved by the server PC, which detects the failureand redesignates another printing apparatus for reprinting.

<Procedure of Processing According to First and Second Embodiments>

The print procedure in an example of network-printing will be describednext separately from the viewpoint of the print manager client PC (toabbreviated as a “client PC” hereinafter) and the print manager serverPM (to abbreviated as a “server PM” hereinafter).

The procedure of processing according to the second embodiment will bedescribed below with reference to FIGS. 23 and 24. However, thoseskilled in the art can understand that executing all processes shown inFIGS. 23 and 24 is not always necessary for the present invention. Forexample, processing according to the first embodiment can be achieved bycausing the server PM to execute, for example, steps S2201, S2202,S2205, S2211, S2212, S2213, and S2214 of FIG. 24.

FIG. 23 is a flowchart illustrating the procedure of print processingexecuted by the client PC. The client PC is the PC1 or PC2 in FIG. 2. Instep S2101, the client PC creates the printing conditions of a file tobe printed and transmits the conditions to the server PM. In step S2102,the client PC checks whether a transmission result has been receivedfrom the server PM. The client PC waits until reception of thetransmission result.

Upon receiving the notification from the server PM in step S2102, theclient PC transmits print information including the printing conditionsand print data to the designated printing apparatus in step S2103. Theprinting conditions created in step S2101 are sent as parameters to thedriver software of the designated printing apparatus. In step S2104, theclient PC notifies its user that printing is progressing in thedesignated printing apparatus. In step S2105, the client PC checks againwhether a print processing notification has been received from theserver PM, and waits until confirmation of the print processingnotification.

If the print processing notification represents an abnormal end in stepS2106, the client PC executes error processing in steps S2107 and S2108.In step S2107, the client PC notifies the user of error details andalternative information from the server PM. In step S2108, the client PCresends the print information to the designated alternative printingapparatus in consideration of the error details, for example,instructing print start from the middle. The client PC then waits forthe notification from the server PM again in step S2105.

If the print processing notification represents a normal end, the clientPC discards the held print data in step S2109. In step S2110, the clientPC notifies the user that the designated printing apparatus has endedthe print processing. The print data is assumed to be held up to the endof processing in consideration of a failure. At last, in step S2111, theuser who has received the print processing notification goes to thedesignated printing apparatus to pick up the printed product, thusending the print processing viewed from the client PC.

FIG. 24 is a flowchart illustrating the procedure of print processingexecuted by the server PM. The server PM is, for example, the PM 204 inFIG. 2. In step S2201, the server PM receives printing conditions fromthe client PC. In step S2202, the server PM analyzes the receivedprinting conditions. In the analysis processing, the server PM selectsan optimum printing apparatus in consideration of the printability ofthe designated printing apparatus and service details corresponding tothe current power threshold (convenience priority and power savingpriority).

For example, when power threshold 4 in FIG. 16 is selected (when thetotal power consumption is equal to or lower than power threshold 4),the PRN1 that is the designated printing apparatus is selected. Whenpower threshold 5 in FIG. 16 is selected (when the total powerconsumption is higher than power threshold 4), the PRN2 that is thedesignated printing apparatus is selected. As shown in FIG. 15, the PRN1has higher performance, although the power consumption is high. Althoughthe power consumption of the PRN2 is lower than that of the PRN1, theperformance is also lower than that of the PRN1.

Alternatively, when, for example, power threshold 4 is selected (whenthe total power consumption is equal to or lower than power threshold4), as shown in FIG. 16, the user can select the PRN1 or PRN3. On theother hand, when power threshold 5 is selected (when the total powerconsumption is higher than power threshold 4), the user cannot selectthe PRN1. Hence, when the user designates the PRN1, and power threshold4 is selected, the server PM selects the PRN1 designated by the user.However, when power threshold 5 is selected, the server PM does notselect the PRN1 designated by the user. In this case, the server PM canselect the PRN2 that is the designated printing apparatus.

In step S2203, the server PM determines whether the designated printingapparatus can print. Cases in which printing is impossible include, forexample, a case in which the designated printing apparatus is faulty anda case in which the designated printing apparatus still has a printrequest in queue. Upon determining that the designated printingapparatus cannot print, the server PM selects an optimum temporaryprinting apparatus and executes power control processing based on thepower control condition table 1601 in FIG. 16 in step S2204. Morespecifically, the temporary printing apparatus corresponding to theselected power threshold is selected. When power threshold 5 isselected, and the PRN2 is faulty, the server PM selects the PRN1 orPRN3. In step S2205, the server PM notifies the client PC of theselected printing apparatus. On the other hand, if the currentdesignated printing apparatus has no problem in step S2203, the serverPM notifies the client PC of it as the selected printing apparatus instep S2205. When an optimum temporary printing apparatus is selected,the server PM notifies the client PC of the printing apparatus.

Referring to FIG. 16, when power thresholds 1 to 9 are selected, each ofall the PRN1 to PRN3 is designated as the designated printing apparatusor temporary printing apparatus. However, the present invention is notlimited to this. For example, when power threshold 7 is selected, thePRN2 may be designated as the designated printing apparatus, whereas thePRN1 and PRN3 may be designated as undesignatable printing apparatuses.In this case, when power threshold 7 is selected, the PRN2 that is thedesignated printing apparatus is selected even if it cannot immediatelyprint. That is, the PRN2 prints after its trouble such as a fault orpaper jam has been removed, or the print request in queue of the PRN2has been processed. On the other hand, when power threshold 6 isselected, and the PRN2 that is the designated printing apparatus cannotprint, the PRN1 or PRN3 that is the temporary printing apparatus can beselected.

After having notified the PC of the selected printing apparatus, theserver PM checks in step S2206 whether a print processing notificationhas been received from the selected printing apparatus. In step S2207,the server PM measures the time until reception of the print processingnotification. If the time is equal to or shorter than a predeterminedtime, the server PM waits. If the time has exceeded the predeterminedtime, the server PM determines that an error has occurred, and executeserror processing in steps S2208 and S2209.

In step S2208, the server PM selects an optimum alternative printingapparatus based on the printing conditions and the current power controlstate. The current power control state means the currently selectedpower threshold. The alternative printing apparatus is selected based onthe printing conditions and the power control condition table 1601 inFIG. 16.

In step S2209, the server PM transmits the error details (in this case,time-out) and alternative printing apparatus information to the clientPC so as to request to resend the print information. Then, the processreturns to step S2206 to wait for the print processing resultnotification from the alternative printing apparatus again. If the printprocessing result notification from the selected printing apparatusrepresents an abnormal end in step S2210, the server PM executes theerror processing in steps S2208 and S2209, as described above. Thiserror is different from the time-out error in step S2209 in that theerror details to be sent in step S2209 is what is sent as the printprocessing result (for example, a jam error or an expendable error). Ifthe print processing result represents a normal end, the server PMnotifies the client PC of the print processing result in step S2211.

In this embodiment, a description has been made assuming that the clientPC transmits the print information to the printing apparatus after theserver PM has notified the client PC of the selected printing apparatusin step S2205. However, for more reliable handling, the client PC andthe server PM may exchange information representing that the printinformation has been transmitted to the selected printing apparatus. Inaddition, when executing the error processing in steps S2207 and S2208,the server PM may confirm the error details by acquiring the statusinformation of the printing apparatus.

Next, in step S2212, the server PM calculates the total accumulatedpower consumption of the printing system based on the printing resultfrom the selected printing apparatus. This embodiment assumes that theaccumulated power consumption or total accumulated power consumptionrequired for the print action of the selected printing apparatus iscalculated or measured on the printing apparatus side. However, asdescribed with reference to FIGS. 11A to 11C, power consumptioncalculation of each printing apparatus can be executed by either of theserver PM and the printing apparatus. The printing system indicates allprinting apparatuses under power control by the server PM.

In step S2213, the total power consumption of the printing system iscompared with the current power threshold. If the power consumptionexceeds the power threshold as the result of comparison, the server PMperforms shift to an appropriate power threshold in step S2214. Thismeans that one of the power thresholds other than the first powerthreshold selected first for the power control and closer to Pm isselected as the second power threshold. If the power consumption doesnot exceed the power threshold, the current power control state ismaintained. The shift processing to an appropriate power threshold ispower control based on the power control condition table 1601 in FIG. 16and does not always ensure sequential transition to the power thresholdof next level. For example, when mass print processing is executed, thepower threshold may jump to a power threshold higher by several levelsat once. The print processing viewed from the server PM thus ends.Normally, the minimum power threshold equal to or higher than the totalpower consumption is selected from the plurality of power thresholds.The server PM executes power control of each printing apparatus in theabove-described way in accordance with the selected power threshold.More specifically, the server PM controls each printing apparatus to thepower saving level associated with the power threshold as shown in FIG.16. For example, when power threshold 4 is selected (when the totalpower consumption is equal to or lower than power threshold 4), as shownin FIG. 16, the power saving level of the PRN2 is set to PL4. When powerthreshold 5 is selected (when the total power consumption is higher thanpower threshold 4), the power saving level of the PRN2 is set to PL1. Asdescribed above, the power consumption of the PRN 2 in the standby stateis lower at PL4 than at PL1.

Third Embodiment

In the third embodiment, how to time-serially recalculate and update thepower threshold set in the power control system of the first embodimentwill be described. FIG. 25 illustrates an example of a procedureconcerning power threshold recalculation executed by, for example, aserver PM 204 in FIG. 2.

In step S2301, a power consumption required in the current month iscompared with a monthly target power consumption Pm after the elapse ofthe month. In step S2302, the server PM determines whether the powerconsumption is higher than the target power consumption. If the powerconsumption is equal to or lower than the target power consumption, thatis, if the target power consumption has been achieved, the server PMrecords the difference as a deposit in step S2305 and continues thecurrent power control in the next month.

If the power consumption required in the current month is higher thanthe target power consumption, the server PM determines in step S2303whether the deposit up to the month earlier can cover the excess (debt).Upon determining that the deposit is equal to or larger than the debt,the server PM records the difference as the deposit again in step S2305and continues the current power control in the next month.

Upon determining that the deposit is smaller than the debt, the serverPM subtracts the difference from the total power of the remaining monthsin step S2304, that is, the total power of the remaining months will becalculated by subtracting the debt from the sum of the current depositand the allowable power consumptions of the remaining months. In stepS2306, the monthly target power consumptions of the following months arerecalculated in accordance with the same procedure as that describedwith reference to FIG. 12, using the total power of the remaining monthsupdated to the remainder obtained by subtracting the excess. In stepS2307, the monthly power thresholds are calculated from the monthlytarget power consumptions of the following months. Finally in stepS2308, the power control condition table 1601 is created from themonthly power thresholds. As described above, the recalculation isperformed so that the higher the power consumption required in thecurrent month is, the lower the threshold of the next month is.

In the procedure, the monthly target power consumption has beenexemplified. However, an annual, weekly, or daily target powerconsumption may be used, as a matter of course. In this embodiment, thedescription has been made by way of a deposit/debt system. However, thepresent invention is not limited to this. As another example, anincrease or decrease relative to the target value may be calculatedevery month, and the monthly target power consumptions of the remainingmonths may be recalculated every month.

Other Embodiments

Aspects of the present invention can also be realized by a computer of asystem or apparatus (or devices such as a CPU or MPU) that reads out andexecutes a program recorded on a memory device to perform the functionsof the above-described embodiment(s), and by a method, the steps ofwhich are performed by a computer of a system or apparatus by, forexample, reading out and executing a program recorded on a memory deviceto perform the functions of the above-described embodiment(s). For thispurpose, the program is provided to the computer for example via anetwork or from a recording medium of various types serving as thememory device (for example, computer-readable medium).

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application Nos.2010-145526, filed Jun. 25, 2010 and 2011-117445, filed May 25, 2011,which are hereby incorporated by reference herein in their entirety.

What is claimed is:
 1. An information processing apparatus that includesa storage unit configured to store an accumulated power consumption,within a predetermined period, of a printing apparatus group including afirst printing apparatus and a second printing apparatus whoseperformance and power consumption upon printing are lower than those ofthe first printing apparatus, and upon receiving a print request from aclient, selects a printing apparatus to execute the requested printingfrom the printing apparatus group based on the accumulated powerconsumption, comprising: an acquisition unit configured to acquire theprint request from the client; a selection unit configured to select thefirst printing apparatus when the accumulated power consumption is notmore than a first threshold, and selects the second printing apparatuswhen the accumulated power consumption is higher than the firstthreshold; and an accumulation unit configured to add a power to beconsumed by the printing apparatus selected by said selection unit toprocess the print request to the accumulated power consumption stored inthe storage unit.